Sensitivity of Escherichia coli to atabrine conferred by R factor and its potential clinical significance.
A comparative study of the inhibitory effect of Atabrine on R(-) and R(+) strains of Escherichia coli showed that R(+) cells were killed when grown in the presence of Atabrine, whereas R(-) cells were not. It would appear, therefore, that R factor confers sensitivity to Atabrine on the host cells. The "curing" of R factor from R(+) cells by the ultraviolet light-acridine orange method rendered the "cured" cells more resistant than even the parent R(-) cells. The "cured" cells reinfected by R factor were more sensitive than the "cured" cells but less sensitive than the original R(+) cells. After growth once in Atabrine, and even after subcultures in drug-free medium, the growth of R(+) cells in the presence of Atabrine was more rapid than that of the R(-) cells. R(-) cells made resistant by growing them repeatedly in streptomycin, chloramphenicol, tetracycline, and sulfathiazole in succession also showed a higher degree of sensitivity to Atabrine than the original R(-) cells. When mixtures of R(-) and R(+) cells were grown in 120 mug/ml of Atabrine, R(+) cells were killed and the culture consisted predominantly of R(-) cells. A mixture of R(-) and R(+) cells (1:10,000) inoculated into the Atabrine-containing medium and treated 24 hr later with chloramphenicol was completely killed.
D000166:Acridines / Q000494:pharmacology; D002701:Chloramphenicol / Q000494:pharmacology; D003124:Colorimetry; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development* / Q000528:radiation effects; D005796:Genes; D009154:Mutation; D011796:Quinacrine / Q000494:pharmacology*; D011830:Radiation Effects; D013307:Streptomycin / Q000494:pharmacology; D013432:Sulfathiazoles / Q000494:pharmacology; D013752:Tetracycline / Q000494:pharmacology; D014466:Ultraviolet Rays
D000166:Acridines; D013432:Sulfathiazoles; D002701:Chloramphenicol; D013752:Tetracycline; D011796:Quinacrine; D013307:Streptomycin